Advances in Computed Tomography for Geomaterials: GeoX 2010

Characterization of Shear and Compaction Bands in Sandstone Using X-ray Tomography and 3D Digital Image Correlation

E-M. Charalampidou³ — S.A. Hall² — S. Stanchits³ — G. Viggiani² — H. Lewis¹

¹ Institute of Petroleum Engineering, Heriot-Watt UniversityEdinburgh EH14 4AS, [e-mail]

 

² Laboratoire 3S-R- CNRS/Université Joseph Fourier/Grenoble INPDomaine Universitaire, BP53, 38041 Grenoble, [e-mail]

 

³ Deutsches GeoForschungsZentrum GFZTelegrafenberg, D 423, D-14473 Potsdam, [e-mail]

ABSTRACT. In this work we employ x-ray tomography, 3D digital image analysis and 3D-volumetric digital image correlation techniques to characterize localized deformation phenomena in sandstone. The specimens considered have been deformed in triaxial compression under a range of confining pressures (20-190MPa). Shear or compaction bands were observed, at low and higher confinement respectively. X-ray tomography images have been acquired before and after loading (unconfined) at different spatial resolutions (30 and 90 µm voxel size). The combination of both x-ray tomography and 3D DIC provides insights into the geometry and mechanisms of the localized features.

 

KEYWORDS: sandstone, localization, shear bands, compaction bands, x-ray tomography, 3D digital image correlation

1. Introduction

Porous sandstones generally exhibit strain localization when loaded in triaxial compression. The ...